Buggy code:
public abstract class J2DoPrivHelper { private static String lineSeparator = null ; private static String pathSeparator = null ; public static final String getLineSeparator ( ) { } public static final String getPathSeparator ( ) { } public static final PrivilegedAction < Object > setAccessibleAction ( final AccessibleObject aObj , final boolean flag ) { } public static final PrivilegedExceptionAction < Class < ? > > getForNameAction ( final String className , final boolean initializeBoolean , final ClassLoader classLoader ) { } public static final PrivilegedAction < ClassLoader > getClassLoaderAction ( final Class < ? > clazz ) { } public static final PrivilegedExceptionAction < Field > getDeclaredFieldAction ( final Class < ? > clazz , final String name ) { } public static final PrivilegedAction < Field [ ] > getDeclaredFieldsAction ( final Class < ? > clazz ) { } public static final PrivilegedExceptionAction < Method > getDeclaredMethodAction ( final Class < ? > clazz , final String name , final Class < ? > [ ] parameterTypes ) { } public static final PrivilegedAction < Method [ ] > getDeclaredMethodsAction ( final Class < ? > clazz ) { } public static final PrivilegedAction < URL > getResourceAction ( final Class < ? > clazz , final String resource ) { } public static final < T > PrivilegedExceptionAction < T > newInstanceAction ( final Class < T > clazz ) throws IllegalAccessException , InstantiationException { } public static final PrivilegedAction < ClassLoader > getParentAction ( final ClassLoader loader ) { } public static final PrivilegedAction < URL > getResourceAction ( final ClassLoader loader , final String resource ) { } public static final PrivilegedExceptionAction < Enumeration < URL > > getResourcesAction ( final ClassLoader loader , final String resource ) throws IOException { } public static final PrivilegedAction < ClassLoader > getSystemClassLoaderAction ( ) { } public static final PrivilegedAction < Boolean > deleteAction ( final File f ) { } public static final PrivilegedAction < Boolean > existsAction ( final File f ) { } public static final PrivilegedAction < Boolean > deleteOnExitAction ( final File f ) { } public static final PrivilegedAction < File > getAbsoluteFileAction ( final File f ) { } public static final PrivilegedAction < String > getAbsolutePathAction ( final File f ) { } public static final PrivilegedExceptionAction < String > getCanonicalPathAction ( final File f ) throws IOException { } public static final PrivilegedAction < Boolean > isDirectoryAction ( final File f ) { } public static final PrivilegedAction < Boolean > isFileAction ( final File f ) { } public static final PrivilegedAction < Long > lengthAction ( final File f ) { return new PrivilegedAction < Long > ( ) { public Long run ( ) { <START_BUG> return new Long ( f . length ( ) ) ; <END_BUG> } } ; } public static final PrivilegedAction < File [ ] > listFilesAction ( final File f ) { } public static final PrivilegedAction < Boolean > mkdirsAction ( final File f ) { } public static final PrivilegedAction < Boolean > renameToAction ( final File from , final File to ) { } public static final PrivilegedExceptionAction < URL > toURLAction ( final File file ) throws MalformedURLException { } public static final PrivilegedExceptionAction < FileInputStream > newFileInputStreamAction ( final File f ) throws FileNotFoundException { } public static final PrivilegedExceptionAction < FileOutputStream > newFileOutputStreamAction ( final File f ) throws FileNotFoundException { } public static final PrivilegedExceptionAction < FileOutputStream > newFileOutputStreamAction ( final String f , final boolean append ) throws FileNotFoundException { } public static final PrivilegedExceptionAction < InetAddress > getByNameAction ( final String hostname ) throws UnknownHostException { } public static final PrivilegedExceptionAction < Socket > newSocketAction ( final InetAddress host , final int port ) throws IOException { } public static final PrivilegedExceptionAction < ServerSocket > newServerSocketAction ( final int port ) throws IOException { } public static final PrivilegedExceptionAction < Socket > acceptAction ( final ServerSocket ss ) throws IOException { } public static final PrivilegedAction < Properties > getPropertiesAction ( ) { } public static final PrivilegedAction < String > getPropertyAction ( final String name ) { } public static final PrivilegedAction < String > getPropertyAction ( final String name , final String def ) { } public static final PrivilegedAction < ClassLoader > getContextClassLoaderAction ( ) { } public static final PrivilegedAction < Boolean > setContextClassLoaderAction ( final ClassLoader loader ) { } public static final PrivilegedAction < Thread > newDaemonThreadAction ( final Runnable target , final String name ) { } public static final PrivilegedExceptionAction < InputStream > openStreamAction ( final URL url ) throws IOException { } public static final PrivilegedExceptionAction < Object > getContentAction ( final URLConnection con ) throws IOException { } public static final PrivilegedExceptionAction < ZipFile > newZipFileAction ( final File f ) throws IOException { } public static final PrivilegedAction < Code > newCodeAction ( ) { } public static final PrivilegedAction < TemporaryClassLoader > newTemporaryClassLoaderAction ( final ClassLoader parent ) { } public static final PrivilegedAction < MultiClassLoader > newMultiClassLoaderAction ( ) { } public static final PrivilegedAction < BCClassLoader > newBCClassLoaderAction ( final Project project , final ClassLoader parent ) { } public static final PrivilegedAction < BCClassLoader > newBCClassLoaderAction ( final Project project ) { } public static final PrivilegedExceptionAction < Object > bCClassWrite ( final BCClass bc , final File f ) throws IOException { } public static final PrivilegedAction < BCField [ ] > getBCClassFieldsAction ( final BCClass bcClass , final String fieldName ) { } public static final PrivilegedAction < BCField > getFieldInstructionFieldAction ( final FieldInstruction instruction ) { } public static final PrivilegedAction < BCClass > loadProjectClassAction ( final Project project , final Class < ? > clazz ) { } public static final PrivilegedAction < BCClass > loadProjectClassAction ( final Project project , final String clazzName ) { }

Fix:
return Long . valueOf ( f . length ( ) ) ;